Summers, 20, was injured Wednesday about midnight at a southeast Portland intersection not far from downtown, according to the e-mail sent by his family.
"While no one knows the details of the accident, we are certain he was hit by a moving vehicle that then fled the scene. If anyone saw or heard anything that night, we urge them to come forward and contact the police," the e-mail said.
Summers' family said his condition has been steadily improving and he has been talking to his coaches, who have visited him at Legacy Emanuel Hospital.
The Beavers won the national college baseball title in June, beating North Carolina in the College World Series in Omaha, Neb.
The Oregon State baseball team's Web site says Summers, a graduate of Southridge High School in Beaverton, was redshirted in 2005.
We all wish Rob the best in his recovery.